In an interview, Josep Borrell said, Spain, Ireland and a handful of other EU member states could formally recognize the State of Palestine on May 21.
Borrell confirmed the plans, adding that the Spanish foreign minister, José Manuel Albares, had told him that 21 May was the proposed date.
Borrell had been attending an event to celebrate Europe Day in Madrid along with Albares hours earlier.
Irish diplomatic sources said that a group of European countries is proposing to recognise a Palestinian state during the month of May, with the 21st a possible date, but not set in stone.
The source added that the date could shift to allow other countries, including non-EU country Norway, to move in tandem.
Borrell also mentioned Slovenia as one of the countries that could join the joint recognition after the government in Ljubljana passed a decree on recognizing the Palestinian state earlier on Thursday.
The EU’s top diplomat also added that Belgium could soon follow suit, as it was delaying the recognition while waiting for more countries to get on board.
Malta could also join, having backed a declaration of intent during a March summit of the European Council.
It comes as the UN General Assembly votes on Friday on a resolution to make the State of Palestine a full member of the United Nations, where they currently hold observer status.
Nine of the EU’s 27 member states currently recognise Palestinians’ right to a state according to the so-called 1967 borders, which include the West Bank, the Gaza Strip and East Jerusalem.
Malta, along with eastern states such as Bulgaria, the Czech Republic, Romania and Slovakia, have recognised the Palestinians’ right to statehood since 1988. In 2014, Sweden became the first member state to unilaterally recognise Palestinians’ right to statehood while a member of the bloc.
Although the European Union supports the so-called two-state solution – which would deliver statehood for Palestinians – and is the single biggest donor of aid to Palestinians, it has not yet unanimously backed the recognition of a Palestinian state.